Defibrillator with overridable cpr-first protocol

ABSTRACT

Methods and apparatus are provided for determining a defibrillation treatment protocol in an external defibrillator whereby a user may override a CPR-first default protocol. The method includes following steps configured in a defibrillator controller of issuing an inquiry; waiting for a response to the inquiry for a set time; ordering a CPR treatment protocol if no response is received within the set time; analyzing a response; ordering a CPR treatment protocol upon receiving a non-affirmative response to the inquiry; and ordering a shock treatment protocol upon receiving an affirmative response to the inquiry. Upon selecting a shock treatment protocol, the defibrillator performs a shock analysis under the shock treatment protocol, and either orders a CPR treatment protocol if shock treatment is not indicated by the shock analysis or provides a defibrillation shock if shock treatment is indicated by the shock analysis. Queries may be presented to a user in visual, audible, or both visual and audible format.

This application is a Divisional of U.S. application Ser. No.11/044,871, filed Jan. 26, 2005, which published as Publication No.2006/0167505 on Jul. 26, 2006, the entire content of which is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to external defibrillatorsincluding AEDs and manual defibrillators, and more particularly relatesto interactive defibrillators having CPR prompts for patient treatment.

BACKGROUND OF THE INVENTION

A normal human heart pumping pattern is called a sinus rhythm, and isregulated by the body's biological pacemaker within the upper rightchamber of the heart, which is commonly referred to as the right atrium.This natural pacemaker, which is generally referred to as the sinoatrial(SA) node, sends electrical signals to the right and left ventricularmuscles in the lower chambers of the heart. The ventricular muscles thenexecute the pumping action under control of the SA node. The rightventricular muscle pumps blood to the lungs for oxygenation, and theleft ventricular muscle pumps the oxygenated blood to various parts ofthe body.

In certain circumstances, the normal or sinus heartbeat rhythm may beadversely affected as a result of some type of malfunction in theheart's electrical control system. When this type of malfunction occurs,an irregular heartbeat may result, causing the ventricular muscles topump ineffectively, thus reducing the amount of blood pumped to thebody. This irregular heartbeat is generally referred to as an arrhythmiaand can lead to Sudden Cardiac Arrest (SCA).

It is estimated that approximately two hundred and twenty-five thousand(225,000) deaths per year are attributable to SCA. A particularlyserious type of SCA is known as Ventricular Fibrillation (VF), which isa malfunction characterized by rapid, uncoordinated cardiac movementsreplacing the normal contractions of the ventricular muscles. In thisevent, the ventricular muscles are not able to pump blood out of theheart, and there is no initiation of a heartbeat. VF rarely terminatesspontaneously, and is therefore a leading cause of sudden cardiac death.The unpredictability of VF and other irregular heart beat conditionsexacerbates the problem, and emphasizes the need for early therapeuticintervention to prevent the loss of life.

Defibrillators are devices for providing life-saving electrical shocktherapy to persons experiencing an irregular heat beat, such as VF. Adefibrillator provides an electrical shock to the heart, in order toconvert the irregular heart beat to a normal sinus rhythm. One type ofdefibrillator, an implantable cardioverter defibrillator (ICD), issurgically implanted in patients who are considered likely to needelectrical shock therapy, precluding the necessity of constantmonitoring by medical personnel.

Another commonly used type of defibrillator is the externaldefibrillator, which sends electrical shock pulses to the patient'sheart through external electrodes applied to the patient's chest.External defibrillators may be manually operated, as are typically usedin hospitals by medical personnel or may be semi-automatic,semi-automated, fully automatic, or fully automated devices, where theycan be used in any location where an unanticipated need may occur. Anautomatic external defibrillator is commonly referred to as an AED.

It is well known that time is an important factor in the successfulapplication of electrical shock therapy. The survival rate of personssuffering from ventricular fibrillation decreases by about ten percent(10%) for each minute the administration of a defibrillation shock isdelayed. It is therefore desirable to minimize the time duration betweenpowering up an external defibrillator and administering the electricalshock therapy to the patient. It is also estimated that the rate ofsurvival for SCA victims averages less than two percent (2%) whendefibrillation is delayed ten (10) minutes or more.

In a typical usage of a defibrillator, the defibrillator electrodes areattached to the patient prior to delivery of a defibrillation shock. Thedefibrillator can also monitor the patient's condition and physiologicalparameters. This data can be measured and analyzed, and then anappropriate therapy determined. If a shock is recommended, thedefibrillator charges to an appropriate level and applies the shocktherapy in a desired format. One or more of these activities can be doneby medical/emergency personnel, as in the case of manual defibrillators,or by an automatic or automated process, as in the case of automatic,semi-automatic, automated and semi-automated defibrillators. Theseactions, while necessary, can be disadvantageously time-consuming, andcan delay the administration of the shock therapy.

Additionally, some defibrillators integrate cardiopulmonaryresuscitation (CPR) instructions along with shock treatment. CPR is acombination of techniques including artificial respiration (rescuebreathing) and artificial circulation (chest compression). One purposeof CPR is to provide oxygenated blood through the body, and to thebrain, in those patients where a prolonged loss of circulation placesthe patient at risk. For example after a period of time without restoredcirculation, typically within four (4) to six (6) minutes, cells in thehuman brain can begin to be damaged by lack of oxygen. In some cases,shock therapy does not immediately restore a normal heart rhythm;several shocks may be required. In other cases, CPR should beadministered prior to any defibrillation therapy. Thus, for somepatients the appropriate treatment calls for a combination of shocktherapy and CPR while other cases may call for shock therapy first.

Many defibrillators also include a CPR protocol. A CPR protocoltypically uses voice prompts and/or a form of interactive display thatguides a user in when to apply CPR methods and shock therapy. ACPR-first protocol has been proposed for use with some defibrillators.Under this protocol, the defibrillator is configured to prompt CPR asthe first type of therapy to be given to a patient. In such a device thedefibrillator may also include ECG (electrocardiogram) capability inorder to monitor patient conditions. One example of an externaldefibrillator with CPR prompts is described in U.S. Pat. No. 6,356,785.Another example is described in U.S. Pat. No. 6,334,070. The CPRprotocol includes prompts which indicate when CPR should be applied. Theprompt may be in the form of a visual/graphical display, an audiodisplay, or some other form of communication.

Referring now to FIG. 1 there is illustrated a flow chart that describesa CPR-first defibrillator protocol. A usage of the defibrillator beginswhen it is brought to the scene of an emergency and activated 2. Thefirst action 4 of the machine is to instruct a CPR therapy to the user.After issuing the CPR instructions, and any attendant routine of queriesand responses within the CPR protocol, the machine then performs ananalysis 6 of the patient's ECG to determine if it is advisable todeliver a defibrillating shock 8. This analysis is referred to as “shockanalysis” in this document. It is noted that in this system a CPR-firstinstruction is the automatic, default action of the device.

While it is advantageous to integrate CPR and shock therapy, there areinstances in which CPR first, prior to shock therapy, is not theappropriate patient treatment. In these cases, shock therapy should beadministered first, and any delay in doing so is potentially adverse tothe patient. Nevertheless, in those systems that have a defaultCPR-first protocol, it is required that a user first pass through theCPR prompts in order to reach the shock treatment protocol

Hence there exists a need for an improved defibrillator and an improvedmethod for operating a defibrillator. Namely, there is a need for adefibrillator, and especially an external defibrillator, that addressesone of more of the above-noted drawbacks and limitations. It would bedesired to provide a defibrillator and a control system thereof thatreduces the inherent time delays associated with shock administration inexternal defibrillators. In addition, it would be desired to provide adefibrillator that includes convenient interactive features so thatoutput and input can be quickly received and supplied by a humanoperator/user. Finally, it would be desired to provide a defibrillatorthat, by virtue of the foregoing, offers an improved level of responseand patient treatment. The present invention addresses one or more ofthese needs.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a defibrillator with an overridableCPR-first protocol. In one embodiment, and by way of example only, thereis provided a method for selecting a treatment protocol in an externaldefibrillator with CPR-first set as a default treatment protocol whereinthe method comprises the steps of: activating a defibrillator at anemergency scene; generating a query whether to bypass the CPR-firstprotocol; initiating a timer upon outputting the query that runs for aset time; ordering the CPR protocol if a response has not been receivedwithin the set time; inputting a response to the query; analyzing theresponse; ordering the CPR protocol if the response to the query isnegative; ordering the CPR protocol if the response to the query is anyresponse other than affirmative; ordering a shock analysis if theresponse to the query is affirmative; providing a defibrillation shockif the shock analysis indicates shock treatment; and ordering the CPRtreatment protocol if the shock analysis indicates no shock treatment.The step of analyzing the response may occur immediately upon receivingan input response. The step of activating a defibrillator may initiate aquery sequence. Additionally, the step of outputting a query may includeoutputting or generating a series of queries or tests. Finally, themethod may include a step of overriding the query and response sequenceby directing an immediate shock therapy analysis. There is additionallyprovided a defibrillator and a method of using the defibrillator thatincludes the above-described method of selecting a treatment protocol.

Other independent features, characteristics, and advantages of thedefibrillator with an overridable CPR-first protocol will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings which illustrate, by way of example, theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart showing a CPR-first defibrillation protocol.

FIG. 2 is an illustration of an external defibrillator system connectedto a patient in accordance with an exemplary embodiment of the presentinvention.

FIG. 3 is a simplified block diagram of an external defibrillator systemin accordance with an exemplary embodiment of the present invention.

FIG. 4 is a simplified flow chart showing a protocol selection methodconfigured in an external defibrillator in accordance with a firstexemplary embodiment of the invention; and

FIG. 5 is a simplified flowchart showing a protocol selection method ofoperating the external defibrillator of FIG. 2 in accordance with asecond exemplary embodiment of the present invention.

DETAILED DESCRIPTION

The following detailed description of the invention is merely exemplaryin nature and is not intended to limit the invention or the applicationand uses of the invention. Furthermore, there is no intention to bebound by any expressed or implied theory presented in the precedingbackground of the invention or the following detailed description of theinvention. Reference will now be made in detail to exemplary embodimentsof the invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Referring now to FIG. 2 there is shown a typical defibrillator system 20that may be used in embodiments of the present invention. The system 20is configured to deliver a defibrillation shock to a patient 22, such asa victim of VF. The defibrillator system 20, includes, but is notlimited to, an external defibrillator 21 having a connection port 23that is configured to receive one or more electrodes (24, 25). Theexternal defibrillator 21 can be any number of external defibrillatorsin accordance with the present invention. For example, the externaldefibrillator 21 can be an Automatic External Defibrillator or AutomatedExternal Defibrillator, semi-Automatic or semi-Automated ExternalDefibrillator, or a manually operated external defibrillator. U.S. Pat.No. 4,610,254 to Morgan and U.S. Pat. No. 6,334,070 to Nova provideillustrative examples of defibrillators, and these two patents arehereby incorporated in their entirety by reference.

The external defibrillator 21 preferably includes a user interface 27.The interface 27 may include an output device such as a display 28 thatis configured to visually present information which may include variousmeasured or calculated parameters of patient 22 and/or other informationto the operator (not shown) of the external defibrillator 21. Display 28is capable of providing information both in textual, numeric, graphical,and/or symbolic format. Information may also be output from thedefibrillator through other means such as but not limited to audiblesignals and/or voice prompts through a speaker or other audio generationdevice. When a display 28 is included, it may comprise any number ofdisplay configurations, e.g., Liquid Crystal Display (LCD) or ActiveMatrix Liquid Crystal Display (AMLCD). Other output devices are alsopossible such as LED's and other light indicators. In some embodiments,a printer may also be included for creating hard copies of data.

The user interface 27 can also include one or more input devices 26 thatare configured to receive commands or information from the operator.Input devices may include, but are not limited to, devices such as keys,buttons, switches, touch screens, keyboards, and keypads. The device mayalso be configured to receive input electronically such as via radiosignals, electrical signals, and digital transfer of information. Thus,for example, in some embodiments, the defibrillator receives input fromelectrodes positioned on patient 22. In one embodiment, thedefibrillator is additionally configured to receive input in the form ofhuman voice commands Thus a receiving device such as a microphone isincluded, along with the necessary means to convert voice signals torecognizable controller commands.

Electrodes 24, 25 are typically multifunction electrodes in that theyare configured both to provide defibrillation therapy and to sense oneor more physiology and/or physical parameters of the patient 22 that arereceived by the external defibrillator 21 at the connection port 23.This is a typical configuration in an AED type device; it will beunderstood by those skilled in the art that electrodes may be designeddifferently for different machines. Other defibrillators, including forexample manual defibrillators, may also have an additional set ofelectrodes (not shown), in addition to the multifunction electrodes,used to receive ECG information. These additional electrodes, ECGelectrodes, are generally smaller than therapeutic/multifunctionelectrodes, and ECG electrodes typically plug into a separate port (notshown) than the therapeutic/multifunction electrodes. As is understoodin the art, ECG electrodes typically have a three wire lead, thoughother arrangements are possible. The signals provided by the one moreelectrodes (24,25) are preferably evaluated by the externaldefibrillator 21 to determine, among other things, whether adefibrillation shock should be applied to patient 22 in accordance withtechniques known to those of ordinary skill in the art. In someembodiments this external defibrillator 21 can also evaluate the signalsprovided by the one more electrodes 24, 25 to determine the waveformparameters of the defibrillation shock (e.g., sinusoidal, monophasic,biphasic, truncated) as well as the shock magnitude and duration. As isunderstood in the art, manual defibrillators may allow for a manualselection of shock parameters.

A variety of physiological data and signals of the patient 22 can besensed by the defibrillator through the electrodes 24, 25 or thoughother sensors. For example, conventional phonocardiogram (PCG)transducers can be used to convert acoustical energy of the patient'sheart to electrical energy for production of a PCG waveform.Additionally, electrical activity of the patient's heart can beconverted for production of an electrocardiogram (ECG) waveform.Transthoracic impedance and other physiological signals of the patientmay also be detected. This data represented by this information can becollected and processed in the controller of the defibrillator. Asrelated in more detail further on, this data may be used, for example,to determine without user input whether a CPR override is appropriate.

Referring to FIG. 3, a simplified block diagram of the externaldefibrillator 21 is illustrated in accordance with an exemplaryembodiment of the present invention. The external defibrillator 21preferably includes a controller 31, the user interface 27 (e.g.,switches or buttons 26 and/or display 28 as shown in FIG. 2), apre-amplifier/measuring circuit 32, a charging mechanism 33 that caninclude a power source 34 and a switch 35 to couple the power source 34to the one or more energy storage devices (e.g., capacitors) 36 and anenergy delivery circuit 37, which is illustrated as a switch 38 that isconfigured to selectively couple the one or more energy storage devices36 to the connection port 23 under the control of the controller 31. Theenergy delivery circuit 37 can be implemented with any number of circuitconfigurations. For example, in a biphasic circuit, an H-bridge circuitcan be used in accordance with the present invention. The controller 31can be a single processing unit or multiple processing units and can beimplemented with software, hardware, or a combination of hardware andsoftware. The controller 31 is configured to at least partially controlthe operation of the external defibrillator 21, including control ofcharging the one or more energy storage devices 36. Controller 31further controls input and output to the device, including displaymethods, and any sequencing of queries and responses.

An AED is generally designed for use by a “first responder,” a user whowould typically be the first person to arrive on the scene of a medicalemergency. A first responder may be a layperson with minimal or no AEDtraining AEDs are being made to be interactive so as to be able toprovide a level of guidance to a first responder. This has been foundparticularly useful with those devices designed for use by laypersons,or others with minimal emergency response training. As previouslystated, a CPR-first protocol is being proposed for use in some AEDs.

However, there are several instances in which the optimal method oftreatment once a defibrillator has been deployed at the emergency sceneis to first provide a shock therapy, and not to first provide CPRtherapy. Some non-limiting examples of these instances include thefollowing situations.

1. The defibrillator is brought to an emergency scene where the patienthas already been receiving CPR. In this instance the action taken inresponse to the CPR protocol prompts given by a defibrillator with aCPR-first protocol would further delay defibrillation, while it mayoffer little or no benefit to the patient.

2. A defibrillator is brought to an emergency scene very rapidly, withina few minutes of a patient collapse (about 2-3 minutes). Such asituation may arise in a home rescue situation. In this scenario CPR maynot provide any additional benefit, but may compromise patient survivalby delaying shock therapy.

3. The person responding to the emergency is not capable of effectivelyadministering CPR. For example, the emotional distress of the emergencymay be too great to permit the person to effectively perform CPR. Inanother example, the responding person may not know how to perform CPRor not remember CPR skills. Or, the responder may simply be physicallyunable to perform effective CPR. Poorly or inadequately performed CPRmay delay defibrillating shock therapy while providing little or nobenefit to the patient, and reduce chances of patient survival.

4. The person had an impendent cardiac arrest. Caregivers are alreadytending to the patient in distress when the cardiac arrest occurs andthe AED is already at the scene. It this situation, the patient maybenefit more from an immediate shock, rather than from CPR.

In each of these cases, it would be useful to allow the user to movedirectly to a defibrillation shock protocol. This protocol includesshock analysis and the provision of a defibrillating shock if the shockanalysis advises provision of a shock. Thus, it has been conceived todevise a defibrillator with a functionality that allows for the user tobypass or override the CPR routine. Thus the defibrillator configurationcan allow for a CPR-first therapy; however, the system allows a user toquickly override this default CPR routine and have the device applydefibrillation shock protocol.

In operation, the overriding system generates an inquiry output uponactivation. The query is to determine whether any conditions, such aswould indicate a CPR override situation, are present. The queries may besingle or multiple.

The inquiry may occur in any of several ways. In one embodiment, theinquiry occurs by voice prompt. In another embodiment, the inquiryquestion is displayed in text on a display screen of the defibrillator;alternatively, the inquiry is presented in graphical symbolic display.In one preferred embodiment, the inquiry comprises a combination screendisplay with audio signal. Thus, for example, the defibrillator devicemay display an inquiry question, and at the moment this is displayed themachine also generates a sound signal. The signal may be any knownalerting sound such as a bell, whistle, or electronically generatedprompt. The sound signal is chosen so as to help draw the user'sattention to the visual display.

In yet another embodiment, the inquiry is performed by the device itselfIn that instance the machine may perform the inquiry by performing aroutine that analyzes physiological data of the patient. Thephysiological data can be obtained through electrodes or other sensorsapplied to the patient that are also coupled to the defibrillator fortransmission of data through a hard-wired connection or through othermeans. Such as for example by radio signal or other wirelesscommunication means.

After issuing the inquiry, the system waits for a response indication tobe input. Again, the response to the inquiry may be registered by thedefibrillator in any of several ways. In one embodiment, a microphonereceives an oral reply. The audio signal is converted to an acceptableelectrical/digital format. A voice recognition module, implementedthrough software, analyzes the signal and records the input signal. Itcan also determine whether a response has been received.

In another embodiment, the response is manually signaled. A usermanipulates one or more input devices such as buttons or touch screens.These input devices may be part of a keypad or keyboard. Alternatively,the buttons may be standalone indicators for quick activation, such asbuttons marked “HELP” or “CPR OVERRIDE” or “CPR BYPASS”. Preferably, theoverriding system allows an operator the option of issuing a singlecommand by which to quickly bypass the CPR protocol and move directly tothe electrical therapy protocol.

In still a further embodiment, a response is determined by the device.This response is determined by internal analysis of data receivedthrough electrodes or other sensors as mentioned above. In thisembodiment, the inquiry may also be an internal inquiry within thecontroller or device. An output of the inquiry external to the deviceneed not occur.

In one embodiment the system allows some waiting period between the timeat which the inquiry is issued and the time for receiving the response.The waiting period can be affected by a number of factors such as theimplementation, experience with the device, and the speed of using it.Approximately 2 to 15 seconds is one possible waiting period. If abypass response has not been input into the device by the expiration ofthe waiting period, the system proceeds to a CPR function.

If a response is inputted into the system, the response is analyzed. Thesystem determines whether to revert to the default CPR-first protocol orwhether to override the CPR-first protocol and proceed to a shockanalysis. A negative response, a non-response (delay exceeds waitingperiod time) or a response other than an affirmative response (anon-affirmative response), may be set to trigger the CPR-first protocol.An affirmative response, in reply to the inquiry, may trigger the CPRoverride. In a further related embodiment, the system can be set so thatwhen CPR is recommended, if the system does not detect the performanceof CPR within a set period of time, e.g. thirty (30) seconds, the CPRprotocol is then skipped.

Different embodiments of the defibrillator with overridable CPR-firstprotocol may generate more than one query. In those embodiments, eachquery is separately timed. A time delay for any query that exceeds theset time moves the system to the CPR protocol. Additionally, eachresponse to each query is separately analyzed. A triggering response toany of the multiple queries may be a command to override the CPR-firstprotocol. Thus, for example, in a series of three questions, the usermay input answers to the first two questions, each in a timely mannerthat does not order the system to override the CPR protocol. However,the third answer may indicate an override command. At that point, thesystem would move to a defibrillation shock protocol—shock analysis andthe provision of a defibrillating shock if the shock analysis advisesprovision of a shock.

Referring to FIG. 4, a flowchart is presented that illustrates a methodof operating the external defibrillator of FIG. 2 in accordance with afirst exemplary embodiment of the present invention. The method of FIG.4 may include processing or programming steps programmed into thatportion of a defibrillator processing system that allows for a CPRoverride. The method begins when the defibrillator is brought to thescene of an emergency and activated 402. The activation 402 of theoverride prompt may begin, for example, when the defibrillator receivesindications that electrodes are in place on the patient and data isbeing received by the machine.

In a next step 404, the system issues an override inquiry. A timingfunction begins upon issuing the inquiry. As stated above, the inquirymay be issued in any combination of several manners—text, audio signal,voice prompt, etc. In one embodiment, the inquiry is issued at thatpoint in the process when the CPR first protocol is otherwise ready toinitiate.

After issuing the inquiry, the system awaits a response 406 for a givenperiod of time. If no response is received when the set time frameexpires, the system proceeds to the normal CPR protocol 410. If thesystem does receive a response within the set time frame, the systemanalyzes 408 the response. It should be noted that the system may bestructured so that once a response is received then the system proceedsimmediately to analyze that response in the succeeding step. In otherwords the system need not wait until the time frame expires beforemoving on to the next step, assuming a response is input. This is doneto minimize the time before a therapy begins. As a practical example, acharging routine involving an internal capacitor need not wait for theentire set time to expire before beginning.

In the next step, the system determines 408 whether the responseauthorizes a CPR override. If it does not, the system proceeds to theCPR protocol 410. If the response does authorize CPR override, then thesystem proceeds, bypasses CPR protocols and proceeds to a shockprotocol, or other treatment protocol appropriate for the patient state.

Having received a response that authorizes the CPR override, the systemnext performs a shock analysis 412. In this step, as is known in thedefibrillator art, the system determines whether the data received fromthe patient indicate a defibrillator shock should be applied. If noshock is indicated, then the system proceeds to the CPR protocol 410.Alternatively, if a shock is indicated, then the system applies theappropriate shock to the patient 414.

In a further embodiment, the system allows for an immediate CPRoverride. In this embodiment of the system the CPR bypass instructionneed not wait for a prompt; instead the system may be commanded toproceed directly to shock mode. Referring to FIG. 5, a flowchart ispresented that illustrates a method of operating the externaldefibrillator of FIG. 2 in accordance with a second exemplary embodimentof the present invention. The system illustrated in FIG. 5 is somewhatsimilar to the system illustrated in FIG. 4. For example, the systemincludes many of the same core steps such as issuing an inquiry, waitingfor a response, analyzing a response, and the default CPR functionality.However, the system includes a difference shown in the OVERRIDE CPRblock 502. This is a command that is independent of the otherfunctionality of the system. Upon receiving this input the systemproceeds immediately to the shock mode, and begins, for example with ashock analysis 412.

In operation, some examples of voice or displayed text inquiries, alongwith corresponding responses to be supplied by the user, include thefollowing non-limiting examples.

1. Has CPR been given so far? (YES/NO) (NO is set as default; if YES,override CPR.)

2. Did the victim collapse less than TMIN ago? (YES/NO) (NO is set asdefault; if YES, override CPR.)

3. Can you perform CPR? (YES/NO) (if NO, override CPR, YES is set asdefault.)

The TMIN is set to a value that is deemed to result in benefit to thepatient from the therapy sequence resulting from the response to thesecond inquiry above. The value of TMIN would preferably be in the rangeof zero (0) to about five (5) minutes.

An alternative implementation of the overridable CPR-first protocol usesa different inquiry format. This format is transparent to theuser/rescuer because the answers to the inquiries are provided by theresults of analysis of patient physiological data by the defibrillatorAn example of this is as follows:

2. Is CPR being sensed? (YES/NO) (NO is set as default; if YES, overrideCPR.)

3. Does the patient have a pulse? (YES/NO) (NO is set as default; ifYES, override CPR.)

4. Does the shock analysis algorithm indicate immediate shock isadvised? (YES/NO) (NO is set as default, if YES, override CPR.)

It is noted that the use of the system includes situations in which thechoice to proceed to a shock protocol is not dependent on ECG analysis.It can result from a response to questions that are input by a user.

In view of the foregoing, it should be appreciated that methods andapparatus are available that allow a defibrillator user to override aCPR-first protocol and move to a shock therapy protocol. This may helpto minimize the inherent time delay between defibrillator activation andthe administration of a defibrillation shock therapy. While a finitenumber of exemplary embodiments have been presented in the foregoingdetailed description of the invention, it should be appreciated that avast number of variations exist. It should also be appreciated that theexemplary embodiments are only examples, and are not intended to limitthe scope, applicability, or configuration of the invention in any way.Rather, the foregoing detailed description will provide those skilled inthe art with a convenient road map for implementing exemplaryembodiments of the invention. It being understood that various changesmay be made in the function and arrangement of elements described in anexemplary embodiment without departing from the scope of the inventionas set forth in the appended claims.

1. A method for determining a defibrillation treatment protocol for anexternal defibrillator comprising: issuing an inquiry with the externaldefibrillator; waiting for a response to the inquiry for a set time;ordering a CPR treatment protocol if no response is received within theset time; ordering a CPR treatment protocol if a non-affirmativeresponse to the inquiry is received; and ordering a shock treatmentprotocol if an affirmative response to the inquiry is received.
 2. Themethod according to claim 1, further comprising: activating the externaldefibrillator; performing a shock analysis under the shock treatmentprotocol; ordering a CPR treatment protocol if shock treatment is notadvised by the shock analysis; and providing a defibrillation shock ifshock treatment is advised by the shock analysis.
 3. The methodaccording to claim 2, in which issuing the inquiry further comprisesissuing the inquiry to a user of the external defibrillator.
 4. Themethod according to claim 2, in which the external defibrillatorincludes a controller and issuing the inquiry comprises issuing theinquiry within the controller.
 5. The method according to claim 2, inwhich the external defibrillator has CPR set as a default initialtreatment protocol, and further comprising: outputting a query to a userwhether to bypass the default initial CPR protocol; initiating a timerupon outputting the query that runs for a set time from the outputtingof the query; ordering the CPR protocol if a response has not beenreceived within the set time from the outputting of the query; if aresponse to the query is received, analyzing the response; ordering theCPR protocol if the response to the query is negative; ordering the CPRprotocol if the response to the query is any response other thanaffirmative; ordering a shock analysis if the response to the query isaffirmative; providing a defibrillation shock if the shock analysisadvises a shock be provided; and ordering the CPR treatment protocol ifthe shock analysis advises no shock be provided.
 6. The method accordingto claim 5, further comprising receiving data from the patient into theexternal defibrillator via ECG probes which are attached to the patientand coupled to the external defibrillator.
 7. The method according toclaim 6, in which the data received from the patient into the externaldefibrillator comprises a response to the query.
 8. The method accordingto claim 5, in which outputting the query further comprises outputting aseries of queries.
 9. The method according to claim 5, furthercomprising overriding, by immediately directing a shock therapyanalysis, the: outputting of the query to the user whether to bypass thedefault initial CPR protocol; initiating the timer upon outputting thequery that runs for the set time from the outputting of the query;ordering the CPR protocol if a response has not been received within theset time from the outputting of the query; if the response to the queryis received, analyzing the response; ordering the CPR protocol if theresponse to the query is negative; ordering the CPR protocol if theresponse to the query is any response other than affirmative; andordering the shock analysis if the response to the query is affirmative.10. The method according to claim 1 further comprising bypassing, byimmediately directing the shock therapy protocol, the: issuing of theinquiry; waiting for the response; and ordering the CPR treatmentprotocol if no response is received within the set time.
 11. An externaldefibrillator for providing a selected treatment protocol to a patientcomprising: a plurality of electrodes affixed to the defibrillator andcapable of being attached to a patient so as to provide shock therapyand to provide patient data to the defibrillator; an input devicedisposed on the defibrillator; an output device disposed on thedefibrillator; a controller disposed in said defibrillator, saidcontroller coupled to said plurality of electrodes, said input device,and said output device, and said controller also configured to: issue aquery as an output; wait for an input response to the query within a settime from the issuance of the query; order a CPR protocol if no responseto the query is received within the set time from the issuance of thequery; analyze a response input received within the set time ; order theCPR protocol if a non-affirmative response is received; and order ashock protocol if an affirmative response is received.
 12. The externaldefibrillator according to claim 11, further comprising an overridefunction that immediately selects a shock treatment protocol.
 13. Thedefibrillator according to claim 11, in which the output devicecomprises a screen.
 14. The defibrillator according to claim 11, inwhich the output device comprises a speaker capable of providing audiblesound to a defibrillator user.
 15. The defibrillator according to claim14, in which the controller is configured to provide voice promptsthrough said speaker as a query.
 16. The defibrillator according toclaim 11, in which the input device comprises a microphone and thecontroller is configured to recognize voice commands spoken through themicrophone as an input response.
 17. The defibrillator according toclaim 11, in which the controller is further configured to receivepatient data from the plurality of electrodes as an input response tothe query.